One type of inkjet-printing device, which is more generally referred to as a fluid-jet device, is a page-wide array inkjet-printing device. In this type of inkjet-printing device, a number of inkjet printheads, which are more generally referred to as fluid-jet printheads, are organized as an array at least substantially perpendicular to the direction of movement of media sheets through the device. The array is a page-wide array in that the printheads extend from one side or edge of the media sheets to the other side or edge of the media sheets. As such, the array is typically stationary during printing; as media sheets are moved past the array, the printheads eject ink onto the media sheets.
A page-wide array inkjet-printing device thus contrasts with another type of inkjet-printing device known as a scanning printhead inkjet-printing device. In the latter type of inkjet-printing device, a scanning inkjet printhead moves, or scans, along a section, or swath, of a media sheet from one side to the other side of the sheet, ejecting ink along this media sheet section as it moves over the section. When printing on the current swath has finished, the media sheet is advanced slightly so that a new swath is incident to the printhead, and the printhead scans over the new swath. This process is repeated until ink has been printed on the media sheet as desired.
In general, page-wide array inkjet-printing devices are typically faster than scanning printhead inkjet-printing devices, in that a complete media sheet can have ink printed thereon in a desired manner more quickly using the former type of inkjet-printing device as compared to the latter type of inkjet-printing device. However, all inkjet-printing devices and other types of fluid-ejection devices are usually susceptible to occasional clogging of printhead nozzles through which ink is actually ejected. Therefore, a purging operation may have to be periodically performed to forcibly clear the printhead nozzles so that they can continue to be used for printing purposes.